1. Field of the Invention
The present invention relates to a substrate insulation device.
2. Discussion of the Related Art
As is known, in integrated electronic circuits, technically known as chips, there is a portion, known as the substrate, on which active and passive elements with possibly mutually different characteristics are produced. The elements are separated by partitions made of a material which is similar to the electrically and physically connected insulating substrate. The substrate of every integrated circuit is placed at the negative voltage which has the highest absolute value. In this manner, the partitions act as insulators among the various active and passive elements of the integrated circuit, allowing operation of the various elements.
There are applications, as described hereinafter, in which, due to applicable statutory provisions or to other kinds of problems, negative electric voltages whose modulus is greater than the negative voltage of the substrate are applied to the integrated circuits.
This fact entails, for example, that the currents involved must be extremely small, similar in value to the so-called leakage current, even if the active elements are at a lower voltage than the substrate.
In order to solve this problem, it is possible to use high-voltage capacitors as well as devices, for main applications, which use a single chip or dual integrated circuits on which most, if not all, of the active components which compose the discrete printed circuit are integrated, thus combining all the functions on a single substrate.
The aim of the present invention is to eliminate or substantially reduce the problems described above by providing a substrate insulation device which solves the problem of the presence of negative voltages whose modulus is greater than the reference voltage of the substrate of the integrated circuit.
Within the scope of the above aim, an object of the present invention is to provide a device which can maintain the functions required by a particular application even if voltages lower than the substrate reference voltage are applied.
Another object of the present invention is to provide a device which is highly reliable, relatively easy to manufacture and at competitive costs.